Patentability of diagnostic tests - Landmark ruling by US Court

Mar 23, 2012

23rd March, 2012

In its judgement delivered on 20th March, 2012 in Mayo Collaborative Services, DBA Mayo Medical Laboratories v. Prometheus Laboratories, the US Supreme Court has held that patents held by Prometheus were not valid. The Supreme Court held that "laws of nature are tools of scientific and technological work" and grant of patents that tie up their use will inhibit future innovations based on them. It also stated that patent statutes could not be interpreted so as to depend on ‘the draftsman’s art’. The order discusses and draws from precedents like Bilski v. Kappos, Parker v. Flook and Dia­mond v. Diehr. The case was closely watched and supported by numerous amici briefs for both parties.

The issue revolved around two patents on the steps involved in use of thiopurine drugs to treat autoimmune diseases. The petitioner Mayo had been a licensee of the patents to diagnostic tests which encompassed administering the drug to a person suffering from immune–mediated gastrointestinal disorder, measuring the level of 6-thioguanine which would indicate the need to increase or decrease dosage of the drug. The Court held that these steps do not add enough to qualify as a patent-eligible process that apply natural laws.

The Supreme Court rejected the Federal Court reasoning that the steps in the claim involved a transformation of the human body or blood taken from the body and thus satisfied the ‘machine or transformation’ test in Bilski. The Supreme Court stated that the ‘machine or transformation’ test is not a definitive test. The respondent had also argued that the patent related to a narrow law and would not inhibit future research. However, the Supreme Court said that there was no precedent or case to distinguish between narrow and broad laws when by implicit exception to 35 U.S.C. 101, laws of nature, natural phenomena and abstract ideas have been held as unpatentable.